Zentyal Server aims at offering small and medium businesses (SMBs) a native drop-in replacement for Windows Small Business Server and Microsoft Exchange Server which can be set up in less than 30 minutes and is both easy to use and affordable.

LIMA-CALLAO is an enterprise accounting program
that respects the conventions and standards
imposed by French law to businesses. It consists
of an accounting engine (CALLAO) and a user
interface for that engine (LIMA).

BusinessTools (business_tools) is a Python package for the handling and validation of commonly used business transaction events such as validating Finnish business IDs or generating bank transfer reference numbers. It supports Finnish company IDs, Finnish bank transfer reference numbers, Finnish bank account numbers (BBAN), and international bank account numbers (IBAN).

Edepol! is an application to manage your shop or your small business. Edepol! lets you to manage customers, invoices, suppliers, and warehouses easily. Edepol! also has a barcode generator function to print labels for your products.

CRM+ is user-friendly, easy-to-understand customer relationship management (CRM) software for getting your company's data centralized and organized. It supports the invoicing, contact management, project management, business history, business tasks, reminders, knowledge base, and many more customer related functions. It was built using the FileMaker database engine. It is available in a single-user edition and a network-capable multi-user edition.

Jledger is a Java Business Accounting API that consists of invoicing, general ledger, stock/inventory control, and other business APIs that will assist Java developers in building business software with ease. It will take care of the business logic like accounting double entry, Stock Balance and management (FIFO), etc., and seamlessly integrate each part of business operation as a whole.

YaBS is enterprise resource planning software that manages products and contacts as basic data, generates offers, orders, invoices, and reminders from it, and includes basic book keeping. It writes PDF or ODF (OpenOffice format) documents, and is a multiuser system. It is the successor of MP Invoicing. It can use any JDBC compliant database as a backend, and works in heterogenous networks, allowing fine grained security settings. It can also be extended with modules.

BOAPI is an implementation of default often used business objects in different programming languages with an identical public interface. It supports PHP 5.3 (with namespaces), C# (.NET port), and Java.